大气混合污染物对大鼠肺脏中血红素氧合酶1表达的影响

通过观察大气污染物引起大鼠肺损伤的病理组织学变化,分析肺组织内血红素氧合酶1（HO-1）的表达量的变化,为大气污染所致肺损伤的生物学标记物的研究提供科学依据。实验方法如下：将30只Wistar大鼠,随机分为3个实验组（3d、7d、30d组）和3个对照组（3d、7d、30d组）,对实验组大鼠染尘染毒后提取所有大鼠肺组织,观察其病理组织学变化;RT-PCR技术检测各组肺组织中HO-1的mRNA表达;Western-blot技术检测各组肺组织中HO-1蛋白的表达。结果显示：实验组（7d及30d）的肺组织病理形态学评分显著高于对照组（7d及30d）,实验组（7d及30d）大鼠肺组织HO-1mRNA表达与对照组相比,具有显著性差异（P均〈0.05）。随着吸入大气混合污染物的时间延长,肺组织内的HO-1蛋白表达水平逐渐增高,实验组（7d及30d）与对照组（7d及30d）相比,差异有显著性意义（P〈0.05）。在吸入大气混合污染物后早期（7d）,HO-1转录水平升高。持续吸入混合大气污染物（30d）,大鼠肺组织出现明显的病理组织学变化,HO-1转录水平、蛋白表达水平均比对照组明显升高。得出结论：可将HO-1作为大气混合污染物所致的肺损伤的早期生物学标记物;采取某些手段增加肺组织HO-1的表达,可能会减少混合大气污染物对肺组织造成的损伤。     

配合比对机制砂混凝土性能的影响

为测试原材料及配合比对全机制砂混凝土性能的影响,对粗细骨料、机制砂级配、水泥、外加剂等原材料各项指标进行了检测,对不同配合比的全机制砂混凝土的各项指标的进行了试验测试,分析了砂率和胶水比对各龄期强度的影响以及强度增长规律。结果表明:原材料各项指标符合规范要求,全机制砂混凝土能达到施工坍落度、可泵性及强度、抗冻、抗渗等性能指标,砂率和胶水比对各龄期强度影响较为明显。用全机制砂混凝土具有经济和环保的双重效益。     

锚杆静压桩群桩效应分析

为促进对桩-土-承台相互作用规律的认识,本文主要运用ABAQUS模拟了锚杆静压桩(方桩)的不同桩长、桩边长、桩间距、桩数以及承台厚度情况下,锚杆静压桩群桩基础的工作性状。桩长的增长和桩数的增加,都会导致群桩效应系数和承台荷载分担比的降低;而随着桩间距增大群桩效应系数和承台荷载分担比增大。这些结论都有助于指导桩基设计,使得桩基设计更符合其实际工作状况。     

赣江南昌段东西河工程整治前后分流比变化研究

近年来,由于不合理的开发利用,赣江下游的两条支流东、西河的分流比发生了较大变化,对河道防洪、通航和城市取水等产生了影响,为此,规划采用工程措施进行河道治理。为了对工程治理效果进行验证,选用Delft3D软件建立了平面二维水流模拟数学模型,并根据实测水文资料对模型进行了验证,对赣江南昌段工程整治后水位、断面流速分布、东西河分流比进行了模拟分析。结果表明,在枯水和洪水条件下,工程整治对东西河分流比的调控作用不明显,裘家洲切滩后上游水位略有降低,下游水位未受影响,断面流速分布更为均匀,东河疏浚工程有增大其过水能力的趋势。分析结果为工程措施的改进提供了依据。     

小功率数码中频稀土永磁发电机组的设计与试验

中频稀土永磁发电机具有功率密度大、体积小、结构简单的特点,以MC68HC908MR32单片机控制为核心的小功率数码中频稀土永磁发电机组,采用"交—直—交"变换,将永磁发电机发出的中频电压变换成单相工频电源电压,样机实测结果表明该机组具有工频电压波形畸变率和电压调整率小、效率高等特点.     

Metabolic and cardiovascular responses to exercise with caffeine

The effect of caffeine on circulation and metabolism was studied during a discontinuous maximal oxygen uptake (VO₂ max) test on a bicycle ergometer. Eight male subjects were chosen for their minimal use of caffeine of which six normally did not ingest caffeinated beverages. Two caffeinated and two decaffeinated (control) trials were administered to each subject following double-blind and counterbalanced testing procedures. One hour before exercise, subjects ingested decaffeinated coffee with or without 350 mg of caffeine anhydrous added. Cardiac output (Q) was measured by a C0₂ rebreathing technique. Compared to control trials, caffeine increased the VO₂ max by an average of 140ml min?¹ (p <0-0·5)l. In addition, during caffeine trials, the average maximal heart rate (HR max) was elevated by 5 beats min^?1 (p<0·01). There were no other statistically significant changes in metabolic (VO₂ and R) and cardiovascular (Q, HR, SV and (a-v) 0₂ diff) variables during either submaximal or maximal exercise. Performance, as measured by total exercise time on the VO₂ max test, was not significantly different (p>0·05). It was concluded that caffeine has a small physiological but a statistically significant effect on VQ₂ max and HR max. During submaximal exercise, caffeine did not significantly effect the cardiovascular system.     

办公建筑用电设备末端节能控制系统设计

随着建筑面积不断增加,人们对室内环境要求日益增强,建筑用电能耗也随之增加.办公建筑中设备末端节能控制设计是减少用电能耗浪费的重要途径和内容.系统结合办公特点、实际需求和室内动态环境,将室内温度、光照度、室内有无人员存在作为主要控制参数,结合办公作息时间表并考虑加班等特殊影响因素,对室内照明、办公插座以及空调等用电设备进行了节能控制设计;同时,系统设置通讯接口,实现数据外传功能,进而对接能耗监测平台.结果表明：在满足办公人员对舒适度要求的前提下,能最大限度的提高建筑用电能效比具有一定的社会和环境效益,开发前景较好.     

Performance of Sewage Sludge Treatment and Electricity Generation by Different Configuration Microbial Fuel Cells

This paper compared the degradation efficiency of sludge organic matters and electric-production by two typical microbial fuel cells——dual-chamber microbial fuel cell(DMFC)and single chamber air cathode microbial fuel cell(SAMFC),and the variations of sludge protein,polysaccharide and ammonia nitrogen within the systems were also investigated.The results showed that the concentration of sludge soluble chemical oxygen demand,protein and carbohydrate of DMFC are higher than these of SAMFC during the systems operation,while DMFC can achieve a better ammonia nitrogen removal than SAMFC.Under the same operation condition,the stable voltage output of DMFC and SAMFC is 0.61 V and 0.37 V;the maximum power density of DMFC and SAMFC is 2.79 W/m3and 1.25 W/m3;TCOD removal efficiency of DMFC and SAMFC is 34.14%and 28.63%for 12 d,respectively.Meanwhile,DMFC has a higher coulomb efficiency than SAMFC,but both are less than5%.The results showed that DMFC present a better performance on sludge degradation and electric-production.